1. Field of the Invention
The present invention relates to the assembly of heat exchanger coils which are adapted to transfer heat between a fluid flowing through a tubular member within the coil and a fluid in contact with the fins of the coil. More specifically, the present invention relates to an apparatus and a method for assembling a plate fin coil adapted to be utilized as a condenser or evaporator of a refrigeration or air conditioning unit.
2. Description of the Prior Art
Plate fin coils utilized in the air conditioning and refrigeration industry are normally manufactured by first stamping or slitting from a coil of plate fin stock the appropriate size fins. The fins are then collected in the appropriate orientation and number to form a coil. Previously formed hairpin tubes are then inserted through the openings within the fins and thereafter expanded forming a mechanical and thermodynamic connection between the tubes and the fins. Thereafter, the partially assembled coil core is degreased, the return bends inserted into the hairpins and subsequently the return bends are soldered or brazed in place. The heat exchanger is then forwarded to storage or to an assembly line for immediate installation within the air conditioning or refrigeration system or unit.
The making of fins is typically accomplished in either a fin press or a fin slitting device to form both the exterior fin shape as well as surface variations on the fin and openings through which the tubular members may be inserted.
Generally, the air conditioning and refrigeration industry presently forms a plurality of single row fins of one or more passes simultaneously from a section of coiled plate fin stock. These individual fins are then collected on stacking rods or within a box or some other means is utilized to form a pile or stack of single row fins ready to be laced with a hairpin tube. This collection of individual rows of fins requires that each row be handled separately, laced separately and otherwise treated separately throughout the manufacturing process.
It is disclosed in U.S. Pat. Nos. 2,977,918 entitled, "Method of Making Heat Transfer Units", and 2,994,123 entitled, "Method of Forming Heat Transfer Units", that a series of plate fins could be manufactured having tabs or tabular portions connecting the adjacent plate fins such that the rows of fins could be separated from each other. These patents disclose bending the plate fin ribbon accordion style such that a sufficient length is utilized to form a fin pack for the coil core. Thereafter the rows of fins are separated from each other prior to any hairpin tube or other tubular member being inserted within the openings of the fins or prior to any other maufacturing process being accomplished on the fin pack. These patents further disclose that multi-row coils may be formed from the continuous fin pack by separating a plurality of rows from the remaining fin pack. However, there is no teaching of lacing the fin pack with hairpin tubes or proceeding with any other process manufacturing steps prior to the separation of the adjacent rows of fins.
The present invention is a plate fin coil utilizing single row fins such that a plurality of fins are stacked to from the fin pack rather than a single row being formed by a fin being bent upon itself numerous times to form the necessary passes for the fin pack. The present invention is further drawn to the fin pack being laced and other process steps being completed prior to the adjacent rows of fins being separated.